Cut-estimator.



No. 871,417. PATBNTED NOV. 19,1307.

0. A. KENYON. OUT ESTIMATOR.

APPLICATION FILED NOV. 20, 1906.

UNITED STATES OTISALLEN KENYON, OF NEW YORK, N. Y.

CUT-ESTIMATOR.

Specification of Letters Patent.

I Patented Nov. 19, 1907.

Application filed Liorcmber 20. 1906. Serial No. 344.2.

T 0 all whom it may concern":

. Beit known that I, OTISALLEN KENYON, a

provide a very cheap and simple devicewhich indicates directly by a very simple manipulation, all of the required computations. 7

With this object in view the invention consists in the features of construction herein after set forth and claimed.

In the drawing: Figure 1 is a diagrammatic view illustrating the principles of the invention; Fig. 2 is a View of a practical device embodying said principles.

In carrying out my invention I make use of two geometrical principles as a basis for the calculations. The first principle employed is the property of similar triangles, the corresponding sides of-which are inthe same ratio to one another. The second principle utilized is the property of the equilateral hyperbole, the product of the ordinates and abscissa of which at all points is constant.

Referring to Fig. 1 of the drawings, A B C is a triangle having sides A C and B C. D B Eis another triangle, having sides D E and B E. Since these triangles :are both right triangles and have a common. angle, they are similar, and since they aresimilar, it follows that the relation of the sides of the large triangle to one anotheris the same as the relation of the sides of the small triangle. This is the first principle utilized.

In order to illustrate the second principle I will consider an equilateral hyperbola described through the point D with the lines B C and B F as coordinates axes. Then the product of the coordinates of anypoint, as, for example, the point D, is the same as the product of the coordinates of any other point, as, for example, G. But the product of the coordinates of any point represents the area of a rectangle having such coordinates as sides. Thus if the parameter of the hyperbola' is known, the area of every rectangle constructed on the coordinate axes and whichhas its corner falling on the. hyperbola is .also. at once ascertained. By having a number of hyperbola with different parameters, all known, it is possible to ascertain the area of an Y rectangle'whatsoever within the limits of t e diagram used.

Referring now toFig. 2, 1 indicates a sheet of cardboard, or any suitable material, and 2 a transparent portion, which may be of celluloid. I'have made the transparent portion 2 in the form of a 45 right triangle, and this triangle has ordinates and abscissa 3 and 4 thereon at unit distance apart.

5 indicate a series of e uilateral hyperbolas, the equations of whic vary in an orderly sequence as follows: in 'y=3, a: y=4, a; y=5, etc., supposing that a; and y are the coordinates of any point.

The marking of the triangle 2 corresponds generall with the diagram (Fig. 1); The diagonai line A B is formed in the practical device by any convenient indicating means, such as a straight edge or a string 6 attached or ivoted at the point 7. The various hyper olas are conveniently marked as shown,

9, 12, 15, 18, etc., corresponding to their parameters or equations and the, ordinate and abscissa lines 3 and 4 are also denoted by numerals to indicate their value.

The operation is as follows: Supposing that it is desired to ascertain the exact dimensions and area of a photo-mechanically reduced plate to be made from an drawing The computer is placed so that t e oint 7 falls at one corner of the drawi an the base line B C lies along one edge. he straight line indicator or string 6 is then swung so as to fall across the opposite corner of the drawing, for exam Is as shown in dotted lines in Fli. 2. It is t on merely necessary to discover w ere any particular ordinate intersects'the straight edge to know all the required computations. For example, if a cut 5 inches long is desired, it will be seen that the ordinate 5 intersects the straight line indicator or string 6 at the point 2.5, so that the cut will be 2% inches igh. This point of intersection lies almost on the hyperbole No. 12, so that the areais substantially 12 square inches. The indication is always near enou h for thepurposes of prices, by consi ering the most adjacent yperbola, or estimating fractional values bet ween two vhyperbolas.

I provide means for carrying the processone step further so as to indicatethe expense of the cut. 9 indicates a plate pivoted at, 10 u on the under side of the sheet 1. This p ate has a handle 11 projecting through an arcuate slot 12 in the sheet 1, so as to swing the plate about'its pivotal point. 13 indicate radial rows of figures each of which repi resents the cost of a cut of certain'area at a certain rice rate. The different rows represent di erent price rates and the different figures in each row stand for diflerent areas. Each of the hyperbola is connected by an indicating line 15 to register with particular figures of any radial row. The particular row which-is moved into operative position is indicated through a slot 16 in the sheet l'by suitable inscriptions on the plate 9, appearin through a slot 17.

hat I claim, is 1. A computing appliance comprising a sheet having a portion ruled with a series of ordinates and abscissa, the location of which is marked 'or denominated, and a series of hype'rbolas, the parameters of which are also marked or denominated, and means pivoted at the intersection of the axes of said hyperbolas for intersecting said ordinates and hyperbolas with a line corresponding to a dia onal of the drawing to be reproduced, where y the vertical dimension of the reproduction desired is indicated by the intersection of the said diagonal with an abscissa, and the area is indicated by the intersection of the diagonal with a hyperbola.

2. A computing appliance comprising a sheet having a portion with ordinates and hy-' perbolas thereon, means for intersecting said ordinates and hyperbolas with a line corre sponding to a diagonal of the drawing to be 40 reproduced, and means movable with respect triangular transparent portion of the sheet v and means pivoted at said apex of the triangular portion for intersecting said ordinates -and hyperbolas with a line corresponding to a diagonal of the drawings to be re-produced.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

OTIS ALLEN KENYON. Witnesses i i WALDO M. CHAPIN, VVALTER CALLAHAN. 

